Scala, Inc. - Hardware FAQ / Hardware Stability Guide

General rules:
PC100 or PC133 SDRAM memory is required for Intel CeleronII and Cyrix C3 CPU's.

PC133 or PC150 SDRAM memory is required for Intel PentiumIII-series CPU's.

PC800-PC1200 RDRAM or PC1600- PC2700 DDR-SDRAM is required for Intel Pentium4,
Pentium4-M, and Pentium4 XEON CPU's

PC133 SDRAM or PC1600- PC2700 DDR-SDRAM is required for AMD CPU's.

Intel Pentium4 systems supporting three different memory architectures are available: SDRAM, DDR-SDRAM, and RDRAM. Scala, Inc. does not recommend the use of SDRAM Pentium4, (or AMD Athlon), systems. If a Pentium4 system with RDRAM is to be considered it MUST support "Dual Bank RDRAM" and be configured with a MINIMUM of * TWO* RIMM modules! From a cost/performance standpoint DDR-SDRAM provides the greatest value.

DDR-SDRAM systems are available with 266, 333, and 400 MHz memory data transfer speeds. The practical performance advantages of 333 and 400 MHz are minimal.

ECC Memory.
In the early days of computers, RAM was often unreliable. Memory would occasionally storeinformation incorrectly or over time "forget" that information had been stored in it at all!Computer designers combated these problems through two mechanisms: Memory Parity and Error Correction Code.

In a "memory parity" design extra memory, typically one part in nine, was used as a 'check' on the preceding eight bits of information. While not correcting bad data, this could at least inform the computer and its software that the data was not valid. As computer memory became more reliable this type of memory design lost favor with computer vendors-the elimination of this 9th bit of memory resulted in a "free" 11% reduction in the cost of RAM!

In an Error Correcting Code, or "ECC" memory design, when small errors occur, which do happen occasionally in most systems, the memory system can actually "fix" the error as if it never happened. Most of the time when these "small errors" do take place without ECC, the casual user would assume that some form of "software error" or "General Protection Fault" had taken place. Quite often it is just as likely that a "random bit-error" occurred.

When implementing a Scala IC Player solution that is intended for a 7x24x365 implementation-Public Information kiosks, Cable TV Channels, etc. the use of ECC memory is strongly recommended.

Meeting SDRAM, DDR-SDRAM DIMM and RDRAM RIMM Specifications
Many modern motherboards require that the xIMM modules you use on them meet [PC100, PC133, PC150 for SDRAM; PC1600, PC2100, PC2400, PC2700, for DDR-SDRAM; PC800, PC1066, or PC1200 for RamBus RDRAM RIMM] specifications. A memory module that meets one of these specifications has passed a set of tests defined by Intel Corp. that certifies that the memory in question can "keep up" with the access demands of Intel 66/100 MHz FSB, (the CeleronII); Intel 100/133 MHz FSB, (the PentiumIII and Pentium4); or the Intel 266/400/533 MHz DDR-FSB, (the Pentium4 and Pentium4 XEON) CPU's . Such xIMM's also have a SDP-EEPROM (Serial Detect Presence-Electronically Erasable Programmable Read Only Memory) chip on them. These chips electronically identifies the capabilities of the xIMM to the computer. Many newer motherboards print a POST (Power-On-Self-Test) message on the screen and simply stop working on power up if the wrong type of memory module has been installed.

To check out the latest Weekly xIMM prices, click here:

http://www.sharkyextreme.com/

Regards,

Scala Technical Support